The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Compact electrical devices such as motors and solenoids are often housed in cylindrical housings which correspond generally to the active components of the device: a rotor surrounded by a cylindrical stator in the case of a motor or a plunger surrounded by a cylindrical coil in the case of a solenoid. Such cylindrical housings are efficient packages for such devices as they generally require a minimum of material and result in a package having minimum dimensions.
Since one end of a typical motor or solenoid will include an output feature, either a shaft or a plunger, it is frequently convenient to arrange the electrical input or terminals on the opposite end. Input connections or terminals so located also maintain the cylindrical symmetry of the housing.
A problem may develop with such an arrangement, however, especially in smaller devices in which the spacing between the motor shaft, solenoid plunger or other electrically components associated with them and the electrical terminals is limited. In such situations, conductive foreign matter may bridge the gap between an electrical terminal and the shaft or plunger and intermittently or permanently short circuit the device.
This problem can be especially acute in motors and solenoids for automotive applications because of the constant demand for weight saving which generally encourages lighter and therefore smaller devices and the fact that they are often exposed to deleterious atmospheric conditions such as dirt, metallic debris and other contaminants and particulates. Furthermore, a failure of the motor or solenoid due to a short circuit to ground may cause consequential failure of related components or controllers. The present invention addresses this difficulty with motors, solenoids and other similar electrical devices.